OMAHA Neb. (Reuters) - Omaha police accidentally shot and killed an audio technician for the long-running reality television show "Cops" while he was recording officers responding to an armed robbery, police said on Wednesday.

Police also shot dead on Tuesday a robbery suspect who was carrying an airsoft pistol that fires plastic pellets but looks like a standard handgun, authorities said.

Sound technician Bryce Dion, 38, from the "Cops" crew was wearing a bulletproof vest, but was stuck by a bullet that went through a gap in the protective shielding under his arm, Omaha police spokesman Michael Pecha said.

The "Cops" crew travels across the United States documenting the work of law enforcement for its television show. Dion along with a cameraman were filming Omaha police Tuesday night when officers responded to an armed robbery at a Wendy's fast food restaurant, Police Chief Todd Schmaderer told a news conference.

Officers confronted Cortez Washington, 32, who fired at officers. The officers shot back, striking the suspect, Schmaderer said. Washington fled the building and collapsed in the restaurant's parking lot, he said.

Washington died at an Omaha hospital a short time later. Washington had a lengthy criminal history, including a previous robbery arrest, police said. Responding police were unaware of his record during the incident.

Investigators determined later that Washington had been carrying an airsoft pistol that fires plastic pellets but looks and functions like a handgun, police said.

Dion, who also entered the restaurant while capturing the incident, was shot once, authorities said.

The three Omaha police officers involved in the shooting were placed on administrative leave for the investigation, Schmaderer said. He identified the officers as Darren Cunningham, 37, Brooks Riley, 35, and Jason Wilhelm, 39.

A grand jury will be convened, he said.

"Cops," which first aired in 1989, came to Omaha in June and planned to film in the city for one more week, officials said.

Officials at "Cops" and Spike TV, which carries the show, could not be reached immediately for comment.

(Reporting by Katie Knapp Schubert in Omaha and Brendan O'Brien in Milwaukee; Writing by Victoria Cavaliere; Editing by Lisa Shumaker)